Temporal Area Maps for Cell Motion Analysis

The temporal area maps (TAM or TAMaps) and the TAM histograms are superb
methods for analyzing cell shape and motility.

To compute a TAMap do the following:

Acquire a time-lapse series of images of cell(s) using an easily
thresholded imaging mode.

Threshold the image and create a binary mask "stack" of
images, where the intensity value "1" is used for each pixel
that the cell covers, and "0" is used for the background.

Add all the image planes of the binary stack together. If a cell
covers a pixel for 10 time intervals (10 image planes), then the
corresponding pixel in the TAMap will have an intensity value of 10. If
no cell ever covers the pixel, its TAMap value will be zero.

Use your image analysis software's image histogram command to (compute
and) display the TAM histogram. (You are using image analysis software
right? Actually, I did the first TAMap by hand for my 1987 Ph.D. thesis
in the laboratory of Dr. Robert Futrelle, at the University of Illinois
Urbana-Champaign.
Tedious but doable for a small data set). Below is a TAMap from a cell
that changed shape but did not move much over 50 timepoints.

For presentation purposes use your image analysis software's
"pseudocolor lookup table" display option to turn the TAMap
from an informative but boring looking black and white image to a
really cool psychedelic image (a picture is worth a thousand words, as
usual).

The TAM histograms are important because one can add (or
average) them together to obtain population statistics. The histograms are
essentially signatures of the cell's (or population) shape changes and motility.
TAM also complements elliptical Fourier analysis (EFA) of cell shapes. In fact,
one might even want to do EFA on either the outer or some of the inner contours
of a TAMap. Feel free to contact me for more information. Even though they were
invented by Bob Futrelle and I in about 1985 (and refined by me from 1987
through the present), we've neglected to publicize them. I am hoping to change
this during my time at CHLA. If you would like to discuss how TAMaps can be of use in your
work, please contact me.

p.s. If you stare at the B&W TAM image long enough
you may notice face profiles on both the left and the right, like one of those
Rorschach or inkblot tests (my thanks to Microsoft
Encarta's psych test page for the correct spelling of Hermann's name). If
you have trouble seeing the profiles from the grayscale image above, I've put a
black&white (binary) version at the bottom of this page.